Chapter 18. Kinesin-Microtubule Stepping Cycle

The hand-over-hand stepping cycle of kinesin I is most similar to the stepping cycle of which of the following?

Remembering that a cycle can start on any step, select the correct order of the following steps in the Kinesin-Microtubule Stepping Cycle:
A-Conformational change causes neck linker to swing forward and dock onto head - trailing head becomes leading head
B-Trailing head release of P_i undocks linker
C-Leading head binds ATP
D-New leading head binds to MT 16 nm ahead of previous site
E-Leading head releases ADP as trailing head hydrolyzes ATP to ADP + P_i

Kinesin 1 is a highly processive motor, because its hand-over-hand cycle of motility along a microtubule (MT) _______

Which two features of the Kinesin-Microtubule Stepping Cycle ensure that one head always is bound tightly to the MT?
A- A head domain binds tightly to the MT in all nucleotide-bound and nucleotide-free states except in the ADP-bound state, which binds only weakly to the MT.
B- The neck linker associates tightly with the ATP-bound state of a head and undocks from the ADP-bound state.
C- The trailing head hydrolyzes ATP to ADP + P_i and releases the P_i to convert that head to the weakly bound ADP state only when the leading head binds to the MT and releases ADP, converting that head to a tightly bound state.
D- Each trailing head moves 16 nm along the MT when it steps forward to become a leading head.